1. Field of the Invention
This invention relates generally to novel benzoylpiperazine esters and to a process for producing such esters.
More particularly, the invention is concerned with a benzoylpiperazine ester represented by the following formula (I): ##STR3## wherein A represents a single bond or an alkylene group, vinylene group, --O--alkylene group or methine group; R.sub.1 represents a bicyclic carbon ring residue which may be substituted with a lower alkyl group, lower alkoxy group, oxo group or nitro group or a halogen atom, or may be partially saturated; a fluorene residue which may contain an oxo group; a fluorenylidene group; an anthracene residue; a phenanthrene residue which may be substituted with a lower alkyl group, or may be partially saturated; a benzofuran residue or thianaphthene residue which may be substituted with a lower alkyl group or lower alkoxy group; a benzopyran residue or benzoazine residue which may be substituted with an oxo group or phenyl group and partially saturated; a phthalimide residue; a benzodiazine residue; an isooxazole residue which may be substituted with a lower alkyl group or phenyl group; or an alkylene dioxybenzene residue or xanthene residue; and R.sub.2 represents an alkyl group, cycloalkyl group, cycloalkylalkyl group or aralkyl group, excepting the case where A is a single bond, R.sub.1 is ##STR4## and R.sub.2 is a methyl group.